Cyclohexane

Formula: C₆H₁₂
Molecular weight: 84.1595
IUPAC Standard InChI: InChI=1S/C6H12/c1-2-4-6-5-3-1/h1-6H2
IUPAC Standard InChIKey: XDTMQSROBMDMFD-UHFFFAOYSA-N
CAS Registry Number: 110-82-7
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Isotopologues:
Other names: Benzene, hexahydro-; Hexahydrobenzene; Hexamethylene; Hexanaphthene; Cicloesano; Cykloheksan; Rcra waste number U056; UN 1145; NSC 406835
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Other data available:
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- Gas Phase Kinetics Database
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Gas phase ion energetics data

Go To: Top, Vibrational and/or electronic energy levels, References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to C₆H₁₂⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	9.88 ± 0.03	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	164.2	kcal/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	159.4	kcal/mol	N/A	Hunter and Lias, 1998	HL

Ionization energy determinations

IE (eV)	Method	Reference	Comment
9.80 ± 0.05	EI	Holmes and Lossing, 1991	LL
10.0 ± 0.03	EI	Arimura and Yoshikawa, 1984	LBLHLM
9.82	EQ	Sieck and Mautner(Meot-Ner), 1982	LBLHLM
9.88 ± 0.10	EQ	Lias, 1982	LBLHLM
9.88	PE	Kovac and Klasinc, 1978	LLK
9.88 ± 0.02	PE	Bieri, Burger, et al., 1977	LLK
9.88	EI	Lossing and Traeger, 1975	LLK
9.89 ± 0.01	PE	Rang, Paldoia, et al., 1974	LLK
9.83 ± 0.05	EI	Puttemans, 1974	LLK
9.84	PE	Puttemans, 1974	LLK
9.88 ± 0.01	PI	Sergeev, Akopyan, et al., 1973	LLK
9.87	PE	Ikuta, Yoshihara, et al., 1973	LLK
9.88 ± 0.01	S	Raymonda, 1972	LLK
9.89	PE	Demeo and Yencha, 1970	RDSH
9.81	PE	Dewar and Worley, 1969	RDSH
9.79	PE	Al-Joboury and Turner, 1964	RDSH
9.88 ± 0.02	PI	Watanabe, 1957	RDSH
11.0 ± 0.2	EI	Hustrulid, Kusch, et al., 1938	RDSH
10.32	PE	Kimura, Katsumata, et al., 1981	Vertical value; LLK
10.3 ± 0.1	PE	Bieri, Burger, et al., 1977	Vertical value; LLK
10.3	PE	Bruckmann and Klessinger, 1973	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C₃H₅⁺	13.20 ± 0.08	C₃H₇	EI	Rabbih, Selim, et al., 1981	LLK
C₃H₆⁺	12.00 ± 0.07	C₃H₆	EI	Rabbih, Selim, et al., 1981	LLK
C₃H₆⁺	11.23 ± 0.04	C₃H₆	PI	Sergeev, Akopyan, et al., 1973	LLK
C₃H₇⁺	13.50 ± 0.08	C₃H₅	EI	Rabbih, Selim, et al., 1981	LLK
C₃H₇⁺	11.49 ± 0.03	C₃H₅	PI	Sergeev, Akopyan, et al., 1973	LLK
C₄H₇⁺	11.21 ± 0.04	C₂H₅	PI	Sergeev, Akopyan, et al., 1973	LLK
C₄H₈⁺	11.15 ± 0.03	C₂H₄	EI	Rabbih, Selim, et al., 1981	LLK
C₄H₈⁺	11.45	C₂H₄	EI	Puttemans, 1974	LLK
C₄H₈⁺	11.08 ± 0.01	C₂H₄	PI	Sergeev, Akopyan, et al., 1973	LLK
C₅H₉⁺	9.88	CH₃	EI	Lossing and Traeger, 1975, 2	LLK
C₅H₉⁺	≤11.06	CH₃	EI	Lossing and Traeger, 1975	LLK
C₅H₉⁺	11.15	CH₃	EI	Puttemans, 1974	LLK
C₅H₉⁺	11.07 ± 0.04	CH₃	PI	Sergeev, Akopyan, et al., 1973	LLK
C₆H₁₁⁺	11.32 ± 0.05	H	PI	Sergeev, Akopyan, et al., 1973	LLK
C₆H₁₁⁺	11.66	H	EI	Pottie, Harrison, et al., 1961	RDSH

De-protonation reactions

C₆H₁₁^- + = Cyclohexane

By formula: C₆H₁₁^- + H⁺ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	418.3 ± 2.0	kcal/mol	Bran	Peerboom, Rademaker, et al., 1992	gas phase; B
Δ_rH°	406.82 ± 0.90	kcal/mol	G+TS	Bohme, Lee-Ruff, et al., 1972	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	409.5 ± 2.2	kcal/mol	H-TS	Peerboom, Rademaker, et al., 1992	gas phase; B
Δ_rG°	>398.00	kcal/mol	IMRB	Bohme, Lee-Ruff, et al., 1972	gas phase; B

Vibrational and/or electronic energy levels

Go To: Top, Gas phase ion energetics data, References, Notes

Data compiled by: Takehiko Shimanouchi

Symmetry: D_3d Symmetry Number σ = 6

Sym.	No	Approximate	Selected Freq.		Infrared		Raman		Comments

Species		type of mode	Value	Rating	Value	Phase	Value	Phase

a₁g	1	CH2 a-str	2930	E	ia		2938 VS p	liq.	FR(2ν₃)
a₁g	1	CH2 a-str	2930	E	ia		2923 VS p	liq.	FR(2ν₃)
a₁g	2	CH2 s-str	2852	C	ia		2852 VS p	liq.
a₁g	3	CH2 scis	1465	C	ia		1465 M p	liq.
a₁g	4	CH2 rock	1157	C	ia		1157 S p	liq.
a₁g	5	CC str	802	C	ia		802 VS p	liq.
a₁g	6	CCC deform + CC torsion	383	C	ia		383 M p	liq.
a₁u	7	CH2 twist	1383	C	1383	gas	ia		Observed in the crystalline state at about ν₉₀ K
a₁u	8	CH2 wag	1157	C	1157	gas	ia		Observed in the crystalline state at about ν₉₀ K
a₁u	9	CC str + CC torsion	1057	C	1057	gas	ia		Observed in the crystalline state at about ν₉₀ K
a₂g	10	CH2 wag	1437	C	1437	gas	ia		Observed in the crystalline state at about ν₉₀ K
a₂g	11	CH2 twist	1090	C	1090	gas	ia		Observed in the crystalline state at about ν₉₀ K
a₂u	12	CH2 a-str	2915	E	2915 M	gas	ia
a₂u	13	CH2 s-str	2860	E			ia		SF(ν₂,ν₁₈,ν₂₆)
a₂u	14	CH2 scis	1437	C	1437 M	gas	ia
a₂u	15	CH2 rock	1030	D	1040 M	gas	ia		FR(ν₂₃+ν₃₂)
a₂u	15	CH2 rock	1030	D	1016 M	gas	ia		FR(ν₂₃+ν₃₂)
a₂u	16	CCC deform	523	A	523 W	gas	ia
eg	17	CH2 a-str	2930	E	ia				SF(ν₁,ν₁₂,ν₂₅)
eg	18	CH2 s-str	2897	E	ia		2897 M vb
eg	19	CH2 scis	1443	C	ia		1443 S dp
eg	20	CH2 wag	1347	C	ia		1347 S dp
eg	21	CH2 twist	1266	C	ia		1266 VS dp
eg	22	CC str	1027	C	ia		1027 VS dp
eg	23	CH2 rock	785	C	785	gas	785 VW dp	liq.	Observed in the crystalline state at about ν₉₀ K
eg	24	CCC deform + CC torsion	426	C	ia		426 S dp	liq.
eu	25	CH2 a-str	2933	A	2933 VS	gas	ia
eu	26	CH2 s-str	2863	A	2863 VS	gas	ia
eu	27	CH2 scis	1457	A	1457 VS	gas	ia
eu	28	CH2 wag	1355	B	1355 W	gas	ia
eu	29	CH2 twist	1261	A	1261 S	gas	ia
eu	30	CH2 rock	907	B	907 S	gas	ia
eu	31	CC str	863	A	863 S	gas	ia
eu	32	CCC deform + CC torsion	248	C	248 VW	liq.	ia

Source: Shimanouchi, 1972

Notes

Very strong

Strong

Medium

Weak

Very weak

Inactive

Very broad

Polarized

Depolarized

Fermi resonance with an overtone or a combination tone indicated in the parentheses.

Calculation shows that the frequency approximately equals that of the vibration indicated in the parentheses.

0~1 cm^-1 uncertainty

1~3 cm^-1 uncertainty

3~6 cm^-1 uncertainty

6~15 cm^-1 uncertainty

15~30 cm^-1 uncertainty

References

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, Notes

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Holmes and Lossing, 1991
Holmes, J.L.; Lossing, F.P., Ionization energies of homologous organic compounds and correlation with molecular size, Org. Mass Spectrom., 1991, 26, 537. [all data]

Arimura and Yoshikawa, 1984
Arimura, M.; Yoshikawa, Y., Ionization efficiency and ionization energy of cyclic compounds by electron impact, Mass Spectrosc. (Tokyo), 1984, 32, 375. [all data]

Sieck and Mautner(Meot-Ner), 1982
Sieck, L.W.; Mautner(Meot-Ner), M., Ionization energies and entropies of cycloalkanes. Kinetics of free energy controlled charge-transfer reactions, J. Phys. Chem., 1982, 86, 3646. [all data]

Lias, 1982
Lias, S.G., Thermochemical information from ion-molecule rate constants, Ion Cyclotron Reson. Spectrom. 1982, 1982, 409. [all data]

Kovac and Klasinc, 1978
Kovac, B.; Klasinc, L., Photoelectron spectroscopy of adamantane and some adamantanones, Croat. Chem. Acta, 1978, 51, 55. [all data]

Bieri, Burger, et al., 1977
Bieri, G.; Burger, F.; Heilbronner, E.; Maier, J.P., Valence ionization enrgies of hydrocarbons, Helv. Chim. Acta, 1977, 60, 2213. [all data]

Lossing and Traeger, 1975
Lossing, F.P.; Traeger, J.C., Stabilization in cyclopentadienyl, cyclopentenyl, and cyclopentyl cations, J. Am. Chem. Soc., 1975, 97, 1579. [all data]

Rang, Paldoia, et al., 1974
Rang, S.; Paldoia, P.; Talvari, A., Ionization potentials of unsaturated hydrocarbons. 2. Mono-substituted cyclopentenes and cyclohexenes, Eesti. NSV Tead. Akad. Toim., 1974, 354. [all data]

Puttemans, 1974
Puttemans, J.P., Ionisation de cycloalcanes (C₅ a C₁₂) en spectroscopie photoelectronique et par impact electronique, Ing. Chim. (Brussels), 1974, 56, 64. [all data]

Sergeev, Akopyan, et al., 1973
Sergeev, Yu.L.; Akopyan, M.E.; Vilesov, F.I.; Chizhov, Yu.V., Photoionization processes in gaseous cyclohexane, and chloro- and bromocyclohexane, High Energy Chem., 1973, 7, 369, In original 418. [all data]

Ikuta, Yoshihara, et al., 1973
Ikuta, S.; Yoshihara, K.; Shiokawa, T.; Jinno, M.; Yokoyama, Y.; Ikeda, S., Photoelectron spectroscopy of cyclohexane, cyclopentane, and some related compounds, Chem. Lett., 1973, 1237. [all data]

Raymonda, 1972
Raymonda, J.W., Rydberg states in cyclic alkanes, J. Chem. Phys., 1972, 56, 3912. [all data]

Demeo and Yencha, 1970
Demeo, D.A.; Yencha, A.J., Photoelectron spectra of bicyclic and exocyclic olefins, J. Chem. Phys., 1970, 53, 4536. [all data]

Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D., Photoelectron spectra of molecules. I. Ionization potentials of some organic molecules and their interpretation, J. Chem. Phys., 1969, 50, 654. [all data]

Al-Joboury and Turner, 1964
Al-Joboury, M.I.; Turner, D.W., Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials, J. Chem. Soc., 1964, 4434. [all data]

Watanabe, 1957
Watanabe, K., Ionization potentials of some molecules, J. Chem. Phys., 1957, 26, 542. [all data]

Hustrulid, Kusch, et al., 1938
Hustrulid, A.; Kusch, P.; Tate, J.T., The dissociation of benzene (C₆H₆), pyridine (C₅H₅N) and cyclohexane (C₆H₁₂) by electron impact, Phys. Rev., 1938, 54, 1037. [all data]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Bruckmann and Klessinger, 1973
Bruckmann, P.; Klessinger, M., Photoelektronenspektren organischer verbindungen. III. Photoelektronenspektren acetylensubstituierter kleiner ringe, J. Electron Spectrosc. Relat. Phenom., 1973, 2, 341. [all data]

Rabbih, Selim, et al., 1981
Rabbih, M.A.; Selim, E.T.M.; Fahmey, M.A., Ionization & fragmentation of cyclohexane, Indian J. Pure Appl. Phys., 1981, 19, 962. [all data]

Lossing and Traeger, 1975, 2
Lossing, F.P.; Traeger, J.C., Free radicals by mass spectrometry XLVI. Heats of formation of C₅H₇ and C₅H₉ radicals and cations., J. Am. Chem. Soc., 1975, 19, 9. [all data]

Pottie, Harrison, et al., 1961
Pottie, R.F.; Harrison, A.G.; Lossing, F.P., Free radicals by mass spectrometry. XXIV. Ionization potentials of cycloalkyl free radicals and cycloalkanes, J. Am. Chem. Soc., 1961, 83, 3204. [all data]

Peerboom, Rademaker, et al., 1992
Peerboom, R.A.L.; Rademaker, G.J.; Dekoning, L.J.; Nibbering, N.M.M., Stabilization of Cycloalkyl Carbanions in the Gas Phase, Rapid Commun. Mass Spectrom., 1992, 6, 6, 394, https://doi.org/10.1002/rcm.1290060608 . [all data]

Bohme, Lee-Ruff, et al., 1972
Bohme, D.K.; Lee-Ruff, E.; Young, L.B., Acidity order of selected bronsted acids in the gas phase at 300K, J. Am. Chem. Soc., 1972, 94, 5153. [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Notes

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, References

Symbols used in this document:

AE Appearance energy

IE (evaluated) Recommended ionization energy

Δ_rG° Free energy of reaction at standard conditions

Δ_rH° Enthalpy of reaction at standard conditions
Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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AE	Appearance energy
IE (evaluated)	Recommended ionization energy
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions

Cyclohexane

Data at NIST subscription sites:

Gas phase ion energetics data

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

Vibrational and/or electronic energy levels

Symmetry: D3d Symmetry Number σ = 6

Notes

References

Notes

Symmetry: D_3d Symmetry Number σ = 6